Roots searching varies greatly from China to the west. Due to the fact that China did not have much an archiving system, everything about your ancestors pretty much exists only in the home villages unless your ancestors are historical figures or they have been government employees. Thus it is essentially to identify and locate the villages at the very beginning. If you are unaware of your ancestral village, you can try looking for clues in photos/documents/gravestones with Chinese characters. Those has proven to be very useful most of the time.